SMRT takes action after train departed with 1 opened door on Thomson-East Coast Line in December 2024

An MRT train on the Thomson-East Coast Line (TEL) departed Gardens by the Bay station with one of its doors open during passenger service on Dec 17, 2024, which investigators later found that procedures for handling a fault were not adhered to.

There were no injuries to persons and no damage occurred, but the safety incident was subsequently reported to the Transport Safety Investigation Bureau (TSIB), which published its final report on Jun 25 after concluding investigations.

Interested in reading more of our future posts?
Follow us on Facebook, Instagram, WhatsApp, and Telegram for the latest updates!

In the final report, the TSIB – a department under the Ministry of Transport – said the incident began during weekday evening peak hours at 6:30pm on Dec 17, when Passenger Vehicle 02 (PV02) had arrived at the Woodlands Bound platform of Gardens by the Bay station.

As PV02 (or Trainset 2002) opened its doors at the station for passengers to board and alight, Door B4 of Car 20024 opened only halfway and remained stuck half-open even when train doors were commanded to close, since its dwell time was up for departure at 6:31pm.

Diagram of Door B4 opened only halfway. (Image: TSIB)

TSIB said it could not determine why Door B4 was stuck, but noted a postulation from rail operator SMRT, who could not find any issue after inspections at the depot, that a hidden foreign object along the doorway, preventing it from opening or moving, was “a possibility”.

The hidden foreign object might also have dropped off from the doorway of the stuck-open Door B4 – which was able to open and close normally when SMRT inspected – during the train’s movement from Gardens by the Bay station to Marina Bay station, added TSIB.

Train hold applied to the train as it could not depart the station

PV02 was not permitted to depart the station as Door B4 was stuck in a half-opened position.

SGTrains understands that this is a safety feature pertaining to door interlocks and the line’s signalling system departure logic, where all active doors must be proven closed and locked before train movement is authorised.

Following that, TEL’s signalling system automatically applied a train hold to PV02, which commanded all train doors and station platform screen doors (PSDs) to reopen. But Door B4 did not budge and remained stuck half-open.

The Train Service Controller (TSC) at the Operations Control Centre (OCC) received an alarm from PV02, indicating that there was a train door fault at Door B4, which the TSC verified by viewing the station’s CCTV cameras.

With the intention of getting Door B4 to close, the TSC, as instructed by the Chief Controller (CC), pressed the train hold release button on the control screen to have the train doors and the PSDs close automatically.

All train doors and PSDs closed, except that Door B4 remained in the stuck half-opened position. This led to TEL’s signalling system applying a train hold to PV02 again, reopening all train doors and PSDs, but Door B4 stayed stuck half-open.

An SMRT staff member on board PV02, known as an Assistant Station Manager (ASM), was contacted by TSC to go to Door B4 to investigate.

While the ASM was on the way to Door B4, TSIB said, “In their eagerness to resolve the matter”, the CC, who believed that releasing the train hold would allow the door to close on its own, instructed the TSC to release the train hold.

TSIB said the TSC and CC knew that the correct procedure was that the TSC needed to seek prior confirmation from the ASM onboard PV02 on whether Door B4 was closed before releasing the train hold.

Despite that, the TSC executed the CC’s instruction to release the train hold. All train doors and PSDs closed again, except the stuck Door B4.

Unsafe train departure with 1 stuck half-opened door

Door Service Switch (DSS) and its positions of the T251 trains on the Thomson-East Coast Line. (Image: TSIB)

The ASM who did a quick check on Door B4 told TSC he could not find any obstacle that could have prevented Door B4 from closing. He was then instructed by TSC to isolate Door B4 in the closed position, but the door was stuck half-open while trying to push it fully closed.

Isolating a train door refers to removing all electrical power to the particular door’s open and closing mechanism by selecting the door service switch (DSS) in the ‘Off’ position. The DSS can be selected in three positions: ‘Normal’, ‘Test’, and ‘Off’.

Without reporting to TSC that Door B4 was still stuck, TSIB said the ASM decided to try selecting the DSS of Door B4 in the ‘Test’ position to get the door to close.

TSIB said the ‘Test’ position “could cause Door B4 to close”, but it is only meant for maintenance purposes and should not be used when the train is on passenger service. TSIB also said SMRT did not teach ASMs about the ‘Test’ position.

The ASM told TSIB that “he had observed the DSS being turned to the ‘Test’ position to open and close the train doors during the testing and commission phase of the TEL”.

As the DSS is located behind the door cover above a door frame, TSIB said, “it is possible” to insert a switch key into the DSS through a small sliding cover to turn the DSS, without opening the door cover. “This was what the ASM did,” added TSIB.

However, only relying on memory, instead of turning the DSS into the ‘Test’ position, the ASM inadvertently turned it into the ‘Off’ position, effectively isolating it, and thereby the stuck open door was not taken into consideration by the signalling system’s departure logic.

With TEL’s signalling system not yet applying another train hold, PV02, authorised for train movement, started departing from Gardens by the Bay station to Marina Bay station with Door B4 still stuck half-open.

This was when the ASM realised he had switched the DSS into the wrong position.

The ASM reported the situation to TSC and stood at Door B4 to ensure that passengers in that carriage would not come near the half-opened door. TSIB noted that there were about 15 passengers in that carriage.

When PV02 arrived at Marina Bay station, OCC asked the ASM to close Door B4 and isolate the door. TSIB said: “According to the ASM, he turned the DSS to the ‘Test’ position and then to the ‘Normal’ position, and Door B4 closed.”

The ASM then selected the DSS into the ‘Off’ position to isolate the door again, and PV02 was able to continue its service.

Procedures for handling a train door fail-to-close fault were not adhered to

In the final report, TSIB found instances in which rail operator SMRT’s standard operating procedure for handling a train door fail-to-close fault was not adhered to.

The ASM did not report to TSC that Door B4 was still stuck and did not wait for OCC’s instructions before attempting on his own to get Door B4 to close by selecting the DSS of Door B4 to the ‘Test’ position, despite knowing it was only for maintenance purposes.

The OCC did not seek prior confirmation from the ASM on whether Door B4 was closed before pressing the train hold release button, which would remove the train hold command.

The TSC, as instructed by the CC, and with the intent of getting Door B4 to close, pressed the train hold release button instead of the train doors close button. Both will command doors to close, but the train doors close button will not release the train hold for the train to depart.

TSIB added: “Had the standard operating procedure been followed and the train doors close command been used while the train hold command was still in effect, the train would not have moved regardless of the DSS switch position.”

Actions taken by the rail operator

New stickers have been pasted on the door cover of T251 trains to indicate the correct way to isolate the particular door through the sliding access cover. (Image: SGTrains)

Rail operator SMRT has issued a reminder to its operational staff on the importance of adhering to the standard operating procedure for handling a train door fault.

As the DSS positions would not be visible without opening the door cover, TSIB said there is a risk of operational staff selecting the wrong DSS position if they rely on their memory when deciding on the turning direction to select.

In response, SMRT has designed a sticker to be pasted on the train door cover to guide its operational staff on the correct way to select the DSS position. TSIB said installation of these stickers is ongoing and is targeted to be completed by the end of July 2025.

When SGTrains visited the TEL to observe the newly pasted stickers on Jul 24, at least four in five trains had the sticker pasted beside the sliding cover of all doors to access the DSS.

In view of the safety actions taken by SMRT, no safety recommendation is proposed by TSIB.

The TSIB’s final report on the incident is available for public viewing on the MOT website.

Recent Posts
Construction of tunnels for DTL2 Extension to begin in second quarter of 2026
Bukit Panjang LRT line will be closed on Jan 25, 2026
Construction of Brickland MRT station along North-South Line to start in first half of 2026

External Links
Final Report: Train Departed a Station with an Open-Door Incident on 17 December 2024 – TSIB/MOT

Images: SGTrains, TSIB.
This article first appeared on SGTrains.
Last updated on 28 Jul 2025.